Process of treating waste sulfite liquors, &amp;c.



'UNITED STATES PATENT OFFICE.

VIGGO DBEWSEN. OF BROOKLYN. NEW YORK. ASSIGNOB TO WEST VIBGIN'LL PULP & PAPER COMPANY, OF NEW YORK. N. Y. A CORPORATION OF DELAWARE.

PROCESS OF TBEA'I'ING WASTE SULFITE LIQUOBS, &0.

Specification of Letters Patent.

Patented Mar. 25, 1919.

Ho Drawing. Original application filed January 9, 1914. Serial No. 811.141. Divided and this application filed December 12, 1917. Serial No. 208,753.

To all whom it 1110 concern:

Be it known hat I. V1060 Dmzwsrx. a citizen of the United States. and resident of the borou h of Brooklyn. county of Kings. cityand btate of New York. have madea certain new and useful Invention Relating to Processes of Treating Waste Sulfite- Liquors. &c.. of which the following is a specification.

This application is a division of mv copending case. Serial No. 811.141. filed January 9. 1914.

This invention relates especially to the treatment of waste sulfite liquors. such as -are iroduced in wood pulp paper manufacture by which the organic compounds therein may be converted bytreatment with caustic alkali or the like. such as soda. lime or carbonate of soda. the mixture being referably heated under pres ure for several tours and then filtered to remove the precipitated lignin compounds. the filtrate apparently containingthe converted lactonic. acids and the like. This filtrate may then be concentrated and heated under pressure. if desired. with caustic soda or the like to the extent of twenty to fifty per cent. or so and then subjected to distillation with superheated steam which separates the acetone or other ketones and alcohols. etc.. this distillation taking place preferably after the causticized mixture has been reduced to a substantially drv con dition by evaporation or admixture of large quantities of caustic lime or the'like. The distillation residue may also be burned and leached to tem verthe soluble alkali material therein and the precipitated lignin compounds also be further treated for conversion into material, etc.

The waste sulfite liquor from pa r disuitahlefc-ausfic such as soda. lime .'etc..

which is "preferably. used in considerable excess and this action which seems to condesirable to ta 1 while still a r into a suitableoo tosixper cenh o .lime. etcx. wi

, liquor at. lngi cert the or anic .ico mpounds is promoted by heating. and r It isin man cases the waste" sulfite liquor the digester and run it 1.1 5 9 digestel 0 mm? an to alkali, such as two stfofcan'stic soda. caustic allowed, to react with the emperatures for several e; a sia.

hours. heat being supplied so as to keep the pressure up to S0 or 100 pounds more or less per square. inch while the mixture is preferably agitated as by the use of suitable stn-rers in the digester, or by using a rotary dlgester or converter to effect this agitation. Such caustic alkali treatment seems to convert the organic compounds in the sulfite liquor, the woody material being apparently converted into hgnin or similar compounds whlchfiflld to precipitate; and certain other orgamc components such as some of the sugars are apparently transformed into various lactonic acids or allied soluble compounds capable of being broken up or producing; on dry distillation with steam under proper conditions acetone or other ketones and alcohols which may be used as solvents for pyroxylin or for the ordinary varnish gums and resins. The sulfurous acid previously combined with the woody material combines with the lime or other earthy alkali used for this conversion. so that it may be precipitated and recovered and used for the original digesting action of the wood or other fibrous materlal. It is furthermore possible since even the soluble inorganic compounds can be subsequently recovered in this process to use instead of calcium bisulfite. sodium sulfite or other normal sulfite compounds for the original digesting action on the wood. etc.. and secure additional advantages in this way.

The converted mixture is preferably separated by filtration which may be more conveniently effected in some cases after carbon-dioxid gas has been percolated through the mixture preferably at considerable pressure which tends to promote the precipitation and aggregation of the particles of the lignin material. The lignin when separated by filtration from the converted mixture usually represents some 30 per cent. or so of the dry weight of the organic matter in the ori a1 sulfite liquor and this lignin materia may of course be used for the manufacture of tanning material and may also be dried to form a finely divided organic compound suitable for use for many purposes. such as for an inert filler in paint. linoleum and other products.

The filtrate secured from the original sulfite digester liquor after such conversion. or

the sulfite liquor waste after the production of grain alcohol from the sulfite liquor by various processes, after first subjecting itto a similar hi h temperature conversion with caustic alkzfii, may be concentrated to a thick, syrupy consistency as by evaporation in suitable multi le efl'ect evaporators, and then may be sub ected to a further caustic alkali conversion by heating it with a large proportion of caustic soda or the like at ordinary, or preferably high temperatures whichl seems to efi'eclt a further conversig: or s ittin u of t e organic compoun possibly ini) simpler lactonic acids or compounds. Caustic soda to the extent of 10 to 50 per cent. or so of the concentrated solution may be used for this alkali converting action and the causticized mixture may then be submitted to distillation with superheated steam or the like in any desired way either by feeding the causticized mixture into a suitable retort with or without a preliminary drying out or evaporation of the mixture. Or i desired the causticized mixture may be made substantially dry or nonfluentb the incorporation of powdered unslaked ime therewith suflicient to combine with the water resent and drive 01! considerable quantities of the water by the heat of slaking so as to convert the causticized material into a dry powder, if desired, when about an equal wei t of the uicklime has been used. It is 0 course un erstood that where a considerable excess of soda, etc., is originally incorporated with the waste sulfite liquor beyond that necessary to neutralize its acid components, this excess of soluble soda or the like would be present with the filtrate containi the material sub uently concentrated an transformed for e dry distillation treatment so that in some cases it would be unneoessa to incorporate additional amounts of a, etc., to efiect this conversion in the manner described.

On distillation of the converted or causticized soluble material with su rheated steam, for example, at 300 to 500 degrees C. or so acetone and other ketones and alcohols are produced to the extent of some 7 or 8 per cent.,of the dry weight of the organic matter in the original sulfite liquor and several per cent. more of heavier oily distillate is also secured besides considerable proportions of other more volatile material some of which is of a gaseous nature an which is sufiiciently inflammable so as to be used for retort heat, and other heating purposes if desired. eproducts of distillation'may be separated or fractionated in any suitable way to separate the more valuab e volatile solvent from the other material whichincludes several cent. of a black oily material substantia ly immiscible with water and of rather light specific gravity. A repeated distillation may be resorted to in a column still for example, or such an ap aratus may be used to separate the original roducts of distillation.

1e distillation residue in the retort may be submitted to still higher heat and may be finally burned in the presence of air and the caustic or other valuable mineral matter may be separated as by leaching with hot water, for example, which takes up the tic present and permits it to be recovered in the form of caustic or carbonate ofsoda for reuse and the remaining insoluble material may, if desired be burned in a suitable kiln to recover the lime.

This invention has been described in connection with a number of illustrative mate rials, proportions, arrangements and orders of steps, to the details of which disclosure the invention is not of course to be limited,

since what is claimed as new and what is desired to be secured by Letters Patent is set forth in the appended claims:

1. The process of treating the waste liquor from the sulfite cellulose manufacture, consisting in boiling the waste liquor with an execs of alkalies under pressure for such a time that the constituents of the waste liquor are transformed into a precipitate of lignin and calcium sulfite and a solution of organic salts, separating said solution of salts from said precipitate, and subjecting said salts to dry distillation with strong bases, particular] h drate of lime, in the presence of pre era ly superheated steam.

2. The process of treating the waste liquor from the sulfite cellulose manufacture, consisting in boiling the waste liquor with an excess of hydrate of lime under pressure for such a time that the constituents of the waste liquor are transformed into a recipitate of hgnin and calcium sulfite an a solution of organic calcium salts, separating said solution of salts from said precipitate, and subjecting said calcium salts to dry distillation with strong bases, particularly hydrate of lime, in the presence of preferably superheated steam.

3. The process of treating the waste liquor 'from'the sulfite cellulose manufacture, consisting in separat' fermentable substances from the liquor di i boiling the remainder of the waste liquor with an excess of alkalies under pressure for such a time that the constituents of the waste liquor are transformed into a precipitate of'lignin and calcium sulfite and a solution of organic salts, separating said solution of salts from said precipitate, and subjecting said salts'to dry tion with strong bases, particularl hydrate of lime, in the presence of prefera ly super heated steam.

4. The process of treating the waste liquor from the sulfite cellulose manufacture, consisting in separatingijgermentable substances from the liquor and iling the remainder of the waste liquor with an excess of hydrate of lime under pressure for such a time that the constituents of the waste liquor aretransformed into a precipitate of lignin and calcium sulfite and a solution of organic calcium salts, separating said solution of salts from said precipitate, and subjecting said calcium salts to dry distillation with strong bases. particularly hydrate of lime. in the presence of preferably superheated steam.

5. The process of treating waste sulfite liquors which consists in incorporatingtherewith an excess of caustic alkali material and simultaneously agitating the mixture while heated for several hours under pressure, to promote the precipitation of the lignin compounds thus produced and filtering oi! the liquid containing converted components in solution, in concentrating such filtrate and heating the same under pressure with 20 to 50 per cent. of caustic alkali material and in 1 subjecting the causticized mixture to distillation with steam at about 300 to 500 degrees centigrade to produce acetone or other ketones and alcohols and additional volatile material.

6. The process of treating waste sulfite liquors which consistsin incorporatingtherewith caustic alkali material and simultaneously agitating the mixture While heated for several hours under pressure, in precipitating the lignin compounds thus produced and filtering off the liquid containing converted components in solution, in concentrating such filtrate and heating the same with a large proportion of caustic alkali material. and in subjecting the causticized mixture to distillation with steam to produce acetone or other ketones and alcohols and additional volatile material.

T. The process of treating waste sulfite liquors which consists in incorporatingtherewith an excess caustic alkali material and simultaneously ieating the mixture for several hours under pressure, in precipitating the lignin compounds thus produced and filtering off the liquid containing lactonic acids or other converted material in solution. in concentrating such filtrate and heating the same with caustic alkali and in drying and subjecting the converted material to distillation with steam at about 300 to 500 degrees centigrade to produce acetone or othler ketones and additional volatile materia S. The process of treating sulfite liquor waste which consists in incorporating therewith an excess of caustic alkali material and heating the same until the sugary components of the waste liquor are converted into lactonic acids or other converted organic material in solution and in drying and subjecting the converted material to distillation at about 300 to 500 degrees centigrade to produce acetone or other ketone or alcohol.

9. The process of treating sulfite liquor waste material which consists in incorporating therewith an excess of caustic alkali material and heating the same until conversion takes place and in distilling the converted material with steam to produce acetone or other ketone or alcohol.

10. The process of treating sulfite liquor waste material which consists in incorporating therewith an excess of caustic alkali material and heating the same until conversion takes place and in distilling the converted material atabout 300 to 500 degrees centigrade to produce acetone or other ketone or alcohol.

15. The process of treating the waste VIGGO DREWSEN. Witnesses:

HARRY L. DUNCAN, Jrssm B. :KAY. 

